Facebook today updated their Mobile iOS application to version 5.1. The update adds more messaging features and easier ways to share photos via the app.

Now when sending and receiving messages, you can see who is active and their last time of activity so you can know when to expect a reply from them. In addition, messaging has never been easier to get to than now, since you can just swipe left on the news feed to reveal your online contacts that can be messaged. The update also brings the ability to choose favorites for your messaging.

Unfortunately, even after updating the application to be quicker with a ton of wonderful new features, Facebook manages to mess up the application yet again. Widespread reports of failures with the Facebook 5.1 update for iOS are popping up on support forums (such as here) and on Twitter that users cannot load their timelines.

So what do these people do? They log out and try to log back in again to see if it remedies the issue. According to the complaints, users are not able to sign back into the application after signing out. Facebook’s mobile application will not accept your login information that you saved in the Settings application from iOS 6 and if you try to log in manually, you will also get the boot:

We took the Facebook update for a spin ourselves and we can confirm the login issues. In fact, the screenshot above is from one of our own devices. The reports of login failure appear to be intermittent, however widespread. Some users even report having the issue on one device and being able to sign in just fine on another.

For now, we recommend just sitting tight with whatever version of Facebook for iOS you have right now until Facebook can rectify the issues plaguing Facebook 5.1. If you choose to take a chance and flip the coin to see if it will work for you, we recommend backing up your current version of Facebook for iOS to iTunes so that if it doesn't work for you you can delete Facebook from your iOS device and re-sync the last working version.

EDIT: Facebook doesn't appear to be giving us any problems logging in anymore. If you're interested in trying version 5.1 yourself, we still recommend that you back up your latest working version of Facebook for iOS through iTunes before doing so in order to prevent any problems. Better safe than sorry!

the only problem i notice was when i tried to upload a photo, the phone froze so I closed and re-opened the app. push notification works on and off still but other than that, I like it. No need for the messenger app now.